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Studying the Aerosol-Radiation-Interaction

with LM-ART

Dominique Bäumer

Max Bangert

Kristina Lundgren

Rayk Rinke

Tanja Stanelle

Bernhard Vogel

Heike Vogel

COSMO LM – ART (ART = Aerosols and Reactive Trace Gases)

Concept:

LM-ART is online coupled.

Identical methods are applied for all scalars as temperature, humidity, and concentrations of gases and aerosols to calculate the transport processes.

It has a modular structure.

Therefore LM-ART can easily be used in the forecast mode.

www-imk.fzk.de/tro/ACP/

Parameterization of the horizontal saltation and the vertical emission flux (Vogel et al, 2006)

3 different Modes (d = 1.5, 6.7, 14.2 µm)

Log normal distributions

Parameterization of the Dust Emissions

Photochemistry

H SO2 4

HNO3

NO2

sun O3

O

O2 O( D)1

H O2

OH

SO2

RCH3

CO

RCHO

NO2

RCO NO3 2

(e.g. PAN)

H O2

CO2

H RCH2RCH O2

O2

HO2

RCH2O2

O2

Staehelin und Dommen (1994)

NO

H2 2O O2

NH3

Interaction of five modes:

• Two modes for SO42-, NO3

-, NH4+,

H2O, SOA, internally mixed.

• One mode for pure soot.

• Two modes for SO42-, NO3

-, NH4+,

H2O, SOA, and soot internally mixed.

condensation of SO4

2-, NH4+, NO3-, SOA

coagulation

Source: homogeneous nucleation of H2SO4/water

Three modes for mineral dust particles + three modes for sea salt particles + pollen

Treatment of the Aerosol Particles

New Routine in LM-ART:

Computation of , b, g for prevailing aerosol concentration

New Routine in LM-ART:

Computation of , b, g for prevailing aerosol concentration

Modified radiation in LM:

Substitution of climatological optical properties based on current aerosol concentrations

Modified radiation in LM:

Substitution of climatological optical properties based on current aerosol concentrations

Transport, Sedimentation, Deposition

LM-ART

, b, g

Refractive inde of aerosols

Mie Calculations

Single scattering albedo (), specific extinction coefficient (b), asymmetry parameter (g)

Optical Properties of the Aerosols

Size distribution, chemical composition of each mode

Case Study: Mineral dust over West Africa in March 2004

Meteosat-8 Image, 2. – 3. März 2004

Results: Fully coupledResults: Fully coupled

March 2, 2004, 12 UTC

March 4, 2004, 12 UTC

Effects on Radiation (4.3.2004, 12 UTC)

Long wave net radiation at the surface

Short wave net radiation at the surface

Sim. A2

Sim. C

Change in cloud cover (4.3.2004, 12 UTC)

%

A2 C

A2 - C

Foreseen simulations for 2005 within WP 2.4

March 2006: 4.3. – 9.3.2006

Data:

- ECMWF analysis (existing)- soil properties in high resolution (B. Marticorena)

Comparison:

- with meteorological stations- with measurements from Slingo et al. (2006)- optical thickness measured by MFRSR in Niamey- upward and downward fluxes (ARM Mobile Facility [RADAGAST – Project]) in Niamey- radiation fluxes in TOA (perhaps) measured by GERB and by CERES broadband instruments on TERRA and AQUA satellites - with AERONET stations- with Lidar measurements (Flament)

Foreseen simulations for 2005 within WP 2.4

January 2006: 15.1. -30.1.2006

Input Data: - ECMWF analysis - soil properties in high resolution (B. Marticorena)- emissions of biomass burning particles (1.1. – 30.1.) (?)- emissions for calculating ozone (26.1. – 30.1.) (?)

Comparison:

- with meteorological stations - with AERONET stations - Flights B159 (19.1) and B160 (21.1., dust and biomass burning) - Lidar Banizoumbou (18.1., dust and bb, Formenti) - Lidar Banizoumbou (15.1., Heese) - dust radiative forcing (17.1., Mallet)